Metabolic, Endocrine + Growth Flashcards
Type 1 diabetes affects 2 in 1000 children. Vast majority are insulin-dependant although incidence of non-insulin-dependant diabetes is rising due to childhood obesity.
It is caused by autoimmune destruction of β-cells in the pancreatic islents of Langerhans. There is a genetic predisposition, which is suggested by the 30-50% concordance in identical twins. Environmental triggers may be involved (viruses or diet).
What is the presentation in children?
- polyuria - nocturnal enuresis in young children
- polydipsia
- extreme hunger
- weight loss
- fatigue, irritability, behavioural changes
- fruity-smelling breath
How is diabetes diagnosed in regards to plasma glucose levels?
- fasting plasma glucose >7.0mmol/L
- random plasma glucose >11 mmol/L
- 2hr plasma glucose OGTT >11 mmol/L
Diabetic Ketoacidosis (DKA) is a metabolic emergency occurring in Type 1 diabetes.
What is are the 3 main clinical characteristics?
- hyperglycaemia → glucose >11mmol/L
- ketones → blood ketones >3mmol/L (urine can be used)
- acidosis → pH < 7.3 or plasma bicarb <18mmol/L
Children + young people w/ a pH of 7.1 or above = mild or moderate DKA, whereas children + young people w/ pH of less than 7.1 have severe DKA
How can children die from DKA?
- cerebral oedema → unpredictable, more common in younger children/newly diagnosed, cause unknown, mortality 25% if oedema develops, minimise risk by slow correction of metabolic abnormalities
- hypokalaemia → preventable by careful monitoring + management
- aspiration pneumonia → insert NGT in children w/ decreased conscious level
What is the pathophysiology of DKA?
- DKA rsults from an absolute or relative insulin deficiency
- most commonly due to infection, poor concordance w/ Rx, puberty or failure of insulin pump
- leads to energy deficit thus fats broken down as alternative energy substrate
- ketones produced are acidotic + create metabolic acidosis
- high blood glucose results in osmotic diuresis leading to severe fluid + electrolyte imbalances
On examination of the child, what are the clinical features of DKA?
- child will physically look unwell
- deep, sighing breathing → Kussmaul breathing
- tachypnoea + subcostal/intercostal recessions
- signs of shock (ISHOCKS)*
- vomiting, dehydration - dry mucus membranes, sunken eyes
- abdominal pain (severe)
- general malaise + non-specific weakness
- ketotic breath
- if fever → suspect underlying infection
*inc resp rate, sinus tachycardia, hypotension, oligouria, cold, klammy, slow cap refill
What investigations need to be done for DKA?
- blood glucose → finger prick
- blood/urine ketones
- blood gas → cap or venous sample
- lab blood glucose, U+Es, creatinine
- 12 lead ECG → hyper/hypo-kalaemia
Why is it particularly difficult to treat children for DKA if this is their first time?
It is important to note that unwell children and their concerned parents can find these acute situations with multiple investigations very upsetting.
This is particularly crucial for first presentations of diabetes because these children will need repeated bloods as an inpatient, followed by a lifetime of blood sugar testing, insulin injections and outpatient clinics.
Getting it ‘wrong’ the first time can have a devastating effect on this trust relationship and so making the experience as pleasant as possible from the offset is vital.
This may mean involving a play specialist or using local anaesthetic cream during cannulation (if the child is stable enough to allow for this).
In management of DKA, the aim is for gradual correction of the metabolic abnormalities. Treatment should be done in an area equipped to monitor the child. Regular medical review is essential.
What is the initial management?
- ABCDE
- A - check airway, consider NG tube to prevent aspiration if reduced conscious level
- B - assess for deep rapid respiration, give 100% high flow oxygen
- C - assess for hypovolaemic shock + replace fluids
- D - check conscious level
- E - check mucus membranes, trunk + limbs (signs of injury, dehydration or sepsis)
The management of children in DKA should always be discussed with the responsible senior paediatrician.
What are principles of fluid replacement in children with DKA?
- requirement = fluid deficit + maintenance
-
fluid deficit:
- assume 10% dehydrated if sevre DKA (pH <7.1)
- assume 5% dehydrated if mild/mod DKA (pH ≥7.1)
-
use reduced volume rules for maintenance fluids
- bc rapid fluid replacement is associated w/ cerebral oedema
- if weight less than 10kg → give 2ml/kg/hour
- if weight 10-40kg → give 1 ml/kg/hour
- if weight more than 40kg → give fixed volume of 40ml/kg/hour
When should IV insulin be commenced for a child in DKA?
- should be delayed 1-2hrs after beginning IV fluid therapy
- as this has been shown to reduce chance of cerebral oedema
- 0.05-0.1 units/kg/hour of soluble insulin
- eg. Actrapid
- check blood glucose + ketones every 1-2hrs
What needs to be done for the patient in DKA, in regards to potassium levels?
- in pts w/ DKA there is depletion of total body potassium
- despite normal or high potassium levels in blood before Rx initiated
- gluconeogenic hormones cause potassium to be transported out of cells into blood
- large amounts of K+ subsequently lost in urine as part of osmotic diuresis
- once insulin started, extracellular K+ in blood taken up by cells via sodium-potassium pump
- it is common to see hypokalaemia on subsequent blood tests
- therefore vital to replace potassium as part of treatment of DKA
- if pt hyperkalaemic on admission, urine output must be documented before further potassium given
- U+Es should be repeated 2hrs after commencing treatment + then at least every 4hrs
- ECG monitoring should continue throughout
When is DKA considered to be resolved?
- once child is clinically well, drinking + tolerating food
- and blood ketones are less than 1mmol/L or pH is normal
- subcut insulin can be started + IV insulin stopped 1hr later
- oral fluids commenced once ketosis resolving + there’s no N+V
- further care involves liasing w/ diabetic team regarding pt + parent education + discharge planning
- children in DKA require 1-1 nursing
How is hypoglycaemia prevented in the child with DKA?
- blood glucose should be monitored closely when giving IV insulin
- blood glucose can fall rapidly
- rehydration fluids should be changed once blood glucose falls to 14mmol/l
- change to 0.9% NaCl w/ 5% dextrose + 20mmol KCl/500mls
Treatment for type 1 diabetes is lifelong and includes blood sugar monitoring, insulin therapy, healthy eating and regular exercise.
What are principles of T1DM management in children?
- blood sugar monitoring → 4x/day
- continuous glucose monitoring → newer method, needle under skin
- insulin + other meds → rapid-acting, short-acting, inter-acting, long-acting
-
insulin delivery options →
- fine needle + syringe
- insulin pen
- insulin pump
- lifestyle → physical activity + healthy eating
What are problems with diabetic control in younger people and children?
- fear of injecting
- viral illness occurs frequently in childhood
- eating too many sugary foods
- making up‘perfect’ blood sugar measurements to please diabetic team
- have to be very organised + activities may be disrupted bc have to take insulin + eat at a particular time
- psychological upset due to problems caused by disease and feeling different to peers
- psychological changes during puberty make it a time of rebellion so adherence may be minimal
- teenage girls often experiment w/ crash diets + may learn that glycosuria ‘aids’ weight loss
- sex hormones + growth hormone antagonise insulin so higher doses of insulin need to be given during puberty
- drinking alcohol → care must be taken bc it inhibits body’s response to raised blood sugar levels + often contains a lot of sugar
- family may not provide enough support or motivation or have poor understanding of the disease
What is growth faltering (failure to thrive)?
- significant interruption in expected rate of growth
- compared with other children of same gender + age
- recognised by examining sequential measurements on growth chart
- shown by fall across 2 or more centile lines
Roughly, what is the expected average weight gain per week for a child?
- 0-3months → 180g per week
- 3-6months → 120g per week
- 6-9months → 80g per week
- 9-12months → 70g per week
